BOSTON — As the Celtics players and coaches staggered off the court, their bid for a couple of historic comebacks having fallen short in a brutal Game 6, Kevin Garnett made a beeline for his coach of six years.

Garnett, dripping with perspiration after another of his age-defying performances, exchanged some personal words with Doc Rivers. Afterward, while addressing the media, Rivers was in disbelief.

“He told me he loved me, and I told him I loved him,” Rivers said. “Kevin always checks on me, which is funny. That’s what he wanted to know, was I OK. I was laughing with our coaches, that’s typical Kevin.”

If the Celtics had beaten the Knicks and not lost, 88-80, to end their season, Rivers was unsure whether Garnett would have been able to give the Celtics as much as the 15 points, 10 rebounds and two steals he delivered in 41 minutes on Friday. But Rivers would have liked to try it. There was a tinge of reflection to Rivers’ postgame comments, as though he knew something about Garnett and Paul Pierce that nobody else did — or at least did not want to admit.

Rivers, Pierce and Garnett huddled together after the game and agreed to speak later, when the emotions of Friday’s loss had lessened. The Celtics stormed back from a 26-point deficit in the fourth quarter to pull within four points late in the game, encapsulating their near-comeback from a 3-0 series deficit into six frantic minutes. The rally fell short, however, and suddenly the entire organization and its fanbase was struck by the realization that an era may be ending in Boston.

“Right now, a lot of emotions, a lot of thoughts go through your head,” Pierce said. “About the season, about what you could’ve done better to keep this season going, about the future. There’s a lot of mixed emotions right now. It’s a tough loss. We’d be happy with a Game 7, but unfortunately we didn’t get it done.”

Garnett, 36, has two years left on the three-year contract he signed last summer. He demonstrated in the final three games of the series that he is playing near the top of his game, and his roughly $12 million salary next season is reasonable given his production as a big man. Rivers momentarily stunned reporters by saying he “didn’t want [Garnett] to go out that way” before clarifying that he meant going out “this season.”

The fate of Pierce, a career-long Celtic, may be more uncertain. The 35-year-old forward is due more than $15 million next season in the final year of his contract, but the team can exercise a $5 million buyout. That would free up valuable money to bring in some new players to help the Celtics — help that even Garnett and Rivers admitted the Celtics need.

No matter how much money Pierce’s buyout would open up, however, a team without Pierce would be less attractive to Garnett. At this point in his career, Garnett no longer is playing for the money. He is playing for the love of the game and for his friend, Pierce.

“One of the big reasons I came here was because of Paul,” Garnett said. “Obviously, you know you want to be in a situation where it’s better. I want to make sure I can always help the team, want to be in a position where I’m giving something. I demand a lot out of myself, physically and from a skill level. I’ll be honest, I’d be lying to you if I said Paul didn’t play into that.”

Rivers has said that he would prefer to coach Garnett, Pierce and even Ray Allen forever, and he did his best to sound hopeful on Friday. At the same time, he seemed resigned to the possibility that one or both remaining members of the so-called “Big Three” could be gone when the Celtics open training camp in the fall. He has already had to face part of that reality without Allen, who signed with the Heat last offseason.

In an emotional news conference, Rivers credited Garnett with providing the example for the Celtics’ competitiveness, which allowed them to fight back in both a series and a close-out game in which they were left for dead. “They wanted to play well. They didn’t, but they wanted to, and you could feel it,” Rivers said. As he has several times in recent years, Rivers also mused over Pierce’s increasingly unique career.

“He’s one of the greatest Celtics to ever play,” Rivers said. “He’s done so much for this franchise, Paul has. We live in a day and time when guys are changing teams like socks, and Paul has chosen to stay here throughout his career when clearly he had all rights to leave. And he chose to stay. I have so much respect for him for that.”

At the end of a long season, the Celtics fought to keep it alive. After season-ending injuries to Rajon Rondo, Jared Sullinger and Leandro Barbosa, they regrouped with the likes of Terrence Williams, Jordan Crawford and Shavlik Randolph. They turned Brandon Bass into a defensive stopper. They found a spark in Jeff Green. They finally unearthed Jason Terry when it mattered. They eyed up a 26-point deficit with their season on the line, and put a scare into a Knicks squad that shrank away under pressure and backed into the second round.

“We had a shot,” Pierce said.

With Pierce and Garnett, the Celtics have always had a shot. The question now becomes whether this was their last one.